This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-035464, filed Feb. 15, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to a semiconductor manufacturing apparatus used in an assembling step of a semiconductor device and method for manufacturing a semiconductor device and, in particular, to a resin encapsulating apparatus for forming a resin sealing body on a semiconductor chip and resin encapsulating method using the resin encapsulating apparatus.
As a package structure of a semiconductor device there are known a ceramics package sealing a chip-like semiconductor substrate with semiconductor elements, such as a semiconductor circuit formed thereon, with the use of a ceramics container made of, for example, alumina, a resin encapsulated package with a resin sealing body formed by a transfer molding method, etc., and a TCP (tape carrier package) package, etc., formed by dropwise supplying a liquid-like resin to a chip-to-lead connection portion on a semiconductor chip (hereinafter referred to as a chip) with the use of a TAB (tape automated bonding) system. As a method for coating a resin sealing body on such a connection portion, there are the above-mentioned method for forming a package by dropwise supplying a given amount of liquid-like resin on such a portion and curing it and a method, etc., of printing a liquid-like resin of a given viscosity on a connection portion with the use of a mask.
The conventional resign encapsulating apparatus for manufacturing the semiconductor device will be explained below with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing a resin encapsulating apparatus for sealing a resin with the use of a given amount extruding method.
The resin encapsulating apparatus using such a given amount extruding method of FIG. 1 has the following structure. A resin 1, such as an epoxy, having a viscosity is contained within a cylinder 2. This cylinder 2 is mounted on the cylinder holder 3. The cylinder holder 3 is arranged on an XYZ drive section 4 movable in XYZ directions (horizontal and vertical directions). The cylinder 2 is connected to a given quantity extruding device 6 via an air tube 5. An air pressure control mechanism is provided at the given quantity extruding device 6. By the air pressure control mechanism, the liquid-like resin 1 of an amount necessary to the sealing operation is extruded from the forward end of the cylinder 2 and coated on a target member (here, a semiconductor chip mounted on a tape carrier).
At the resin encapsulating apparatus, a conveying section 8 is provided for setting a tape carrier 7 to a predetermined position and the liquid-like resin 1 is coated. For example, the tape carrier 7 is conveyed to a predetermined position. Further, the tape carrier 7 is positioned by a positioning block 9 and fixed in place. The cylinder 2 is moved by the XYZ drive section 4 to a coating position on the tape carrier 7. While moving the cylinder 2 in accordance with an initially registered pattern, a given amount of liquid-like resin 1 is coated on the tape carrier 7. By doing so, a predetermined portion of the chip is sealed.
FIG. 2 is a perspective view showing a resin encapsulating apparatus for performing resin sealing by a printing method. The resin encapsulating apparatus using a printing method as shown in FIG. 2 includes a conveying section 11, positioning fixing block 12, mask 13, squeegee 16, up/down drive section 17 and X, Y direction drive section 18. A tape carrier 10 with a chip mounted thereon is conveyed by the conveying section 11 to a predetermined position. Further, the tape carrier 10 is positioned by a positioning fixing block 12 and fixed in place. The fixed tape carrier 10 is moved by the block drive section (not shown) to a predetermined position and, after being lifted, pushed against the mask 13 set over the conveying section 11.
An opening 14 is provided in the mask to correspond to a coating position. A resin 15 of a given viscosity is placed on a predetermined position of the mask 13. The squeegee 16 placed over the mask 13 is moved by the up/down drive section 17 to a position contacting with the mask 13 and further moved by the drive section 18 (moved in the X direction in this case-or in the Y direction) in the X direction (or the Y direction) over the opening 14 of the mask 13. At this time, since a resin 15 is initially extruded on a position between the down position of the squeegee 16 and the opening 14, the resin 15 is filled in the opening 14 by the above-mentioned operation. By doing so, a predetermined portion of the chip is sealed.
These methods have the following problems. In the given quantity extruding method, since the liquid-like resin serving as a resin sealing body for the chip has a considerable high viscosity, it is not possible to control the spreading, etc., of the resin at a time of coating. As a result, there is a problem that a horizontal accuracy of the resin in the horizontal direction (X, Y directions) is lowered. This method is directed to dropwise supplying a given amount of liquid-like resin to a predetermined position to allow it to be spread in its own natural way, thus posing a problem that the thickness of the resin sealing body never becomes uniform and a defective product is produced due to variation, etc., in sealing thickness of the resin.
In the printing system, a given amount of resin (15) is deposited on the mask 13 and, through a repeated printing operation, only a given amount of resin is extruded onto the mask 13 when that amount of resin is lowered. As a result, there occurs a variation in viscosity of the resin, no complete filling of the resin in a filling site occurs, sometimes leaving no resin-filled area. This method takes more resin at a time of finishing the operation and more product costs.
FIGS. 3A to 3D are cross-sectional views showing a resin coating section of a semiconductor device in the printing method using the resin encapsulating apparatus shown in FIG. 2. As shown in FIG. 3A, the tape carrier 10 with a chip 70 mounted thereon is placed on the positioning fixing block 12. The mask 13 having the opening 14 is set on the tape carrier 10. In this state, the resin 15 of a viscous nature is extruded on the mask 13. And the resin 15 is held by the squeegee 16 and, as shown in FIGS. 3B and 3C, the squeegee 16 is moved along the plane of the opening 14. By doing so, the resin 15 is buried in the opening 14. In the case where the resin 15 was so buried by the above-mentioned method, it follows that, since the resin 15 is relatively high in viscosity, it is not fully filled at the corners of the bottom of the opening 14. This poses a problem of producing a defective semiconductor device. Such a problem becomes prominent in a semiconductor device of such a type that the protective resin sealing body and balls for external connection are provided on the same surface side.
The present invention is achieved to solve the above-mentioned task and is directed to providing a resin encapsulating apparatus and method which can enhance dimensional accuracy of a resin sealing body formed on a semiconductor device and prominently reduce occurrence of defective products resulting from an insufficient filling of resin and use the resin very effectively.
In a first aspect of the present invention, there is provided a resin encapsulating apparatus comprising a retaining section for retaining a semiconductor device, a mask set on the semiconductor device and having an opening at which part of the semiconductor device is exposed, an extruding section for extruding a fluidizing resin into the opening of the mask, a first drive section for driving the extruding section, a squeegee for causing a movement of the fluidizing resin present over the opening which is extruded from the extruding section into the opening, and a second drive section for driving the squeegee.
In a second aspect of the present invention, a resin encapsulating apparatus for forming a protective resin sealing body on a semiconductor device in which the resin sealing body and external connection balls are formed on the same surface side of the semiconductor device, the resin encapsulating apparatus comprising a retaining section for retaining the semiconductor device, a mask set on the semiconductor device and having an opening at which, when the mask is set on the semiconductor device, an area of the semiconductor device at which the resin sealing body is to be formed is exposed, an extruding section for extruding a fluidizing resin into the opening of the mask, a first drive section for driving the extruding section, a squeegee for causing a movement of the fluidizing resin present over the opening which is extruded from the extruding section into the opening, and a second drive section for driving the squeegee.
In a third aspect of the present invention, a resin encapsulating method comprises the steps of retaining a semiconductor device, setting an opening-equipped mask on the semiconductor device and exposing part of the semiconductor device, extruding a fluidizing resin into the opening of the mask, and moving a squeegee over the opening of the mask to cause a movement of the fluidizing resin present over the opening which is extruded into the opening.
In a fourth aspect of the present invention, a resin encapsulating method for forming a protective resin sealing body in which the resin sealing body and external connection balls are formed on the same surface side of the semiconductor substrate, the method comprising the steps of retaining the semiconductor substrate, setting an opening-equipped mask on the semiconductor device and exposing, from the opening, an area of the semiconductor device at which the resin sealing body is formed, extruding a fluidizing resin into the opening of the mask, and moving a squeegee over the opening of the mask to cause a movement of the fluidizing resin present over the opening which is extruded into the opening.
According to the resin encapsulating apparatus and method thus obtained, since the fluidizing resin is extruded directly from an extruding section into the opening in the mask, the viscosity of the fluidizing resin never becomes higher and it is possible to fill the fluidizing resin into the opening without leaving any insufficiently filled area. Further, after the fluidizing resin has been extruded into the opening in the mask, the squeegee is moved over the opening along the surface of the mask to remove any excessive fluidizing resin and it is possible to provide a resin sealing body with high positional accuracy in the X, Y and Z directions. It is also possible to freely set the position and shape of the resin sealing body by the configuration of the mask and to freely set the thickness of the resin sealing body by the thickness of the mask. Further, since this eliminates the need to coat a more than necessary amount of fluidizing resin and thus to very effectively use the fluidizing resin.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.